A nested transaction model for multilevel secure database management systems
Elisa Bertino, Barbara Catania, Elena Ferrari · ACM Transactions on Information and System Security · 2001
This article presents an approach to concurrency control for transactions in a Multilevel Secure Database Management System (MLS/DBMS). The major problem is that concurrency control mechanisms used in traditional DBMSs are not adequate in a MLS/DBMS, since they may be exploited to establish covert channels. The approach presented in this article, which uses single-version data items, is based on the use of nested transactions, application-level recovery, and notification-based locking protocols. All these features allow us to develop a concurrency control mechanism that is free of timing channels and avoids many of the shortcomings of the concurrency control mechanisms so far developed for conventional (i.e., flat) transactions, such as transaction starvation and resource wastage.